JP2007162140A - Accessory having white coating film and production method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accessory having a white coating film which exhibits a color tone peculiar to a coating film of platinum or a platinum alloy, hardly degrades appearance quality due to a dent or a damage and shows a sense of quality, and to provide a production method therefor. <P>SOLUTION: The accessory having the white coating film comprises: a base material for the accessory made from a metal or a ceramic; an underlayer formed on the surface of the base material; a titanium carbide layer formed on the surface by a dry plating method; and a decorative coating layer of platinum or a platinum alloy formed on the surface by a dry plating method. Thereby, the accessory acquires the white coating film which hardly degrades appearance quality due to a damage or the like, exhibits the color tone peculiar to the coating film of platinum or the platinum alloy, and shows a sense of quality. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a decorative article (jewelry) having a white coating and a method for producing the same, and more particularly to a decorative article having a hard, platinum-colored or platinum alloy-colored white coating and a method for producing the same.

  Conventionally, watches, necklaces, pendants, brooches, etc., which are decorative items (jewelry), are often made of copper alloy due to processability, material price, and the like.

  However, since the decorative article manufactured using this copper alloy as a raw material has poor corrosion resistance, a plating film is applied to the base material surface by a wet plating method. This plating film is usually composed of a nickel plating film formed by a wet plating method as a base plating film and an outermost layer plating film formed by a wet plating method on the surface of the coating film. When the outermost layer is made of gold, the outermost layer is coated with a gold plating on the surface of the nickel plating by a wet plating method. When the outermost layer is made of white, the surface of the nickel plating is made of a palladium plating film or palladium. An alloy plating film or a rhodium plating film is formed by a wet plating method. The thickness of these plating films is generally formed in the range of 1 to 5 μm.

  In the decorative product as described above, since a plating film containing an expensive noble metal is formed as the outermost plating film in order to obtain corrosion resistance, there is a problem in cost that the price of the decorative product increases. Therefore, in a low-priced decoration, the outermost layer plating film becomes thin, and the corrosion resistance for a long time becomes a problem. In addition, in the production of low-priced ornaments, maintenance of a precious metal plating bath is a major operational problem in order to obtain a stable thin outermost plating film. Furthermore, in order to obtain the outermost plating film having a stable color tone, the skill level of the worker is also a problem. In addition, an inexpensive decorative product having an outermost plating film with a beautiful white color characteristic of platinum or a platinum alloy has not been obtained.

Therefore, the applicant of the present application disclosed in Japanese Patent Application Laid-Open No. H11-33583 as a white ornament, a white ornament in which the surface of a metal substrate is covered with a white hard film and a platinum or platinum alloy film formed on the film surface. .
Japanese Patent Laid-Open No. 3-120355

  However, in this prior art embodiment, a TiN film is formed as a white hard film, and the color tone of the film is a dark gray color or a light gold color. For this reason, even if a platinum or platinum alloy film is formed on the upper layer of the TiN film, it was influenced by the color tone of the white hard film (TiN film), and a beautiful color unique to platinum or a platinum alloy was not obtained.

  Further, when the thickness of the TiN film is thin, there is a problem that the metal base material is dented by an external impact or pressure, and thereby the platinum or platinum alloy film is also dented and scratched. Moreover, since the thickness of the platinum film is 0.1 μm, there is a problem in terms of cost.

Furthermore, if the deposition of platinum or platinum alloy coating on the metal substrate surface fails, the platinum or platinum alloy coating will be peeled off and a platinum or platinum alloy coating will be deposited again. Since the aqua regia is used when the film is peeled off, the white hard film made of TiN is eroded not only to the surface of the metal base material but also cannot be regenerated.

  The present invention is intended to solve the above-mentioned problems, and a color tone peculiar to platinum or a platinum alloy film is obtained.Therefore, there is a high-class feeling, and appearance quality deterioration due to dents and scratches is less likely to occur. An object of the present invention is to provide a decorative product having a high-quality white coating at a relatively low cost and a method for producing the same.

  Another object of the present invention is to form a platinum film or a platinum alloy film again so that the platinum or platinum alloy film can be peeled off without damaging the decorative substrate, the underlayer and the titanium carbide layer. An object of the present invention is to provide a decorative product that can be regenerated and a method for manufacturing the same.

A decorative article having a white coating according to the present invention is a decorative article in which a decorative coating having a white color tone made of a noble metal or an alloy of a noble metal is formed by a dry plating method as an outermost layer.
A decorative substrate made of metal or ceramics;
An underlayer formed on the surface of the substrate;
A titanium carbide layer formed by dry plating on the surface of the underlayer;
The surface of the titanium carbide layer is composed of a decorative coating layer made of platinum or a platinum alloy formed by a dry plating method,
The titanium carbide layer has a thickness of 0.5 to 1.0 μm, and the decorative coating layer is formed of a white coating having a thickness of 0.03 to 0.06 μm.

  Further, it is desirable that the underlayer is made of an alloy containing no nickel formed by a dry plating method or a wet plating method.

  In the decorative article having a white coating according to the present invention, the decorative article base material is made of at least one metal selected from stainless steel, titanium, a titanium alloy, copper, a copper alloy, and tungsten carbide. And

  In addition, the decorative article base material is made of at least one metal selected from stainless steel, titanium, titanium alloy, copper, copper alloy, and tungsten carbide, and the base material surface has a mirror surface, a satin finish, and a hairline pattern. And at least one surface finish selected from a honing pattern, a stamping pattern, and an etching pattern.

Further, the decorative article base material is made of zirconia ceramics, and its composition includes 3 to 7% by weight containing a stabilizer of yttrium oxide (Y ₂ O ₂ ), magnesium oxide (MgO) or calcium oxide (CaO). The stabilized zirconia containing may have a white color tone.

  In addition, titanium (Ti) in which the base material for decorative article is made of a metal other than copper and a copper alloy, or the ceramic, and the base layer formed on the surface of the base material is formed by a dry plating method It may be a film made of chromium (Cr), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb) or tantalum (Ta).

The carbon material content, wherein the ornamental base material is made of a metal other than copper and a copper alloy, or the ceramic, and the base layer formed on the surface of the base material is formed by a dry plating method. 5 to 15 atomic% of titanium carbide (TiC), chromium carbide (Cr ₃ C ₂ ), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tungsten carbide (WC) Or a gradient film formed of a metal compound film made of tantalum carbide (TaC).

  Further, the decorative article base material is made of a metal other than copper and a copper alloy, or the ceramic, and the base layer is formed by a dry plating method, and has a thickness of 0.02 to 0.2 μm, preferably 0. A film having a thickness of 0.05 to 0.1 μm.

  Further, the decorative article base material is made of copper or a copper alloy, and the base layer is formed on the surface of the base material by a wet plating method. It may consist of an amorphous nickel-phosphorus alloy film having a thickness of 3 to 10 μm formed by a wet plating method.

  Further, the decorative material base material is made of copper or a copper alloy, and the base layer is formed by a wet plating method, copper, palladium, copper-tin alloy, copper-tin-zinc alloy, and copper- It may be a coating film having a thickness of 2 to 9 μm made of at least one selected from tin-palladium alloys.

  The decorative article having a white coating according to the present invention includes titanium carbide that forms the titanium carbide layer between the titanium carbide layer and the decorative coating layer, and platinum or a platinum alloy that forms the decorative coating layer. It has a thickness of 0.005 to 0.04 μm.

Further, a stainless steel coating layer having a thickness of 0.05 to 1.5 μm formed by a dry plating method may be provided between the titanium carbide layer and the decorative coating layer.
The stainless steel coating layer comprises carbon 0.01-0.12% by volume, silicon 0.1-1.5% by volume, manganese 1.0-2.5% by volume, nickel 8-22% by volume, chromium 15- It is made of austenitic stainless steel having a composition of 26% by volume and the balance being iron.

  In the decorative article having a white coating according to the present invention, the color evaluation by the L *, a *, b * color system (CIE color system) of the decorative film layer is 85 <L * <95, 1.5 <a. * <4.0, 4.5 <b * <6.5, preferably 88 <L * <92, 1.8 <a * <2.5, 5.0 <b * <5.5 It is characterized by.

Further, Δ values of L *, a *, b * of the decorative coating layer formed on the decorative article base material subjected to various surface finishes,
ΔL * = ± 6.0, Δa * = ± 1.55, Δb * = ± 2.25
It is characterized by being.

  In the decorative article having a white coating according to the present invention, means for forming each layer of the base layer, the titanium carbide layer, the mixed layer, and the decorative coating layer is a sputtering method, an ion plating method, or an arc method. It is characterized by being at least one.

  The decorative article having a white coating according to the present invention has at least one coating formed on a part of the surface of the decorative coating layer by a dry plating method or a wet plating method and having a color tone different from that of the decorative coating layer. It is characterized by being.

  It is desirable that the coating different from the color tone of the decorative coating layer is an alloy containing no nickel.

  The coating film having a color tone different from that of the decorative coating layer may be made of gold, gold alloy, titanium nitride, zirconium nitride, hafnium nitride, or diamond-like carbon (DLC).

  Further, the coating film having a color tone different from that of the decorative coating layer may have a two-layer structure of a lower layer made of titanium nitride, zirconium nitride or hafnium nitride and an upper layer made of gold or a gold alloy.

  Further, a titanium coating and a silicon coating formed on the surface of the titanium coating are provided between the decorative coating layer and a diamond-like carbon (DLC) coating which is a coating having a color tone different from that of the decorative coating layer. Also good.

  The decorative coating layer may be a mixed layer made of titanium carbide forming a titanium carbide layer and platinum or a platinum alloy.

  The decorative article having a white coating according to the present invention is characterized in that the decorative coating layer has a surface hardness (Hv: micro Vickers hardness meter, 5 g load) of 1000 to 2000.

  The decorative article having a white coating according to the present invention is characterized in that the decorative article is a watch exterior part.

The method for producing a decorative article having a white coating according to the present invention is a method for producing a decorative article in which a decorative coating having a white color tone made of a noble metal or a noble metal alloy is formed by a dry plating method as an outermost layer.
Using a material made of metal or ceramics to produce a base material for decorative goods by various processing means;
Forming a base layer on the substrate surface by a dry plating method or a wet plating method;
Forming a titanium carbide layer on the surface of the underlayer by a dry plating method;
Forming a decorative coating layer made of platinum or a platinum alloy as an outermost layer by a dry plating method on the surface of the titanium carbide layer.

  The underlayer is preferably made of an alloy containing no nickel and formed by a dry plating method or a wet plating method.

  In the method of manufacturing a decorative article having a white coating according to the present invention, the decorative article base material is made of at least one metal selected from stainless steel, titanium, titanium alloy, copper, copper alloy, and tungsten carbide. It is characterized by that.

  In addition, the decorative article base material is made of at least one metal selected from stainless steel, titanium, titanium alloy, copper, copper alloy, and tungsten carbide, and the base material surface has a mirror surface, a satin finish, and a hairline pattern. And at least one surface finish selected from a honing pattern, a stamping pattern, and an etching pattern.

Further, the decorative article base material is based on 100 parts by weight of stabilized zirconia powder containing 3 to 7% by weight of a stabilizer of yttrium oxide (Y ₂ O ₂ ), magnesium oxide (MgO) or calcium oxide (CaO). A material containing 20 to 25 parts by weight of a binder is formed by injection molding, and then formed through a roughing process, degreasing, baking, grinding and polishing steps by machining, and has a white color tone. To do.

  In addition, on the surface of the decorative base material made of a metal other than copper and copper alloy, or ceramics, titanium (Ti), chromium (Cr), zirconium (Zr), hafnium (Hf), vanadium ( A film made of V), niobium (Nb) or tantalum (Ta) may be formed by a dry plating method.

In addition, on the surface of a decorative substrate made of a metal other than copper and a copper alloy or the ceramics, titanium carbide (TiC) having a carbon atom content of 5 to 15 atomic%, chromium carbide (Cr ₃ ) as the underlayer. C _2), dry zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tungsten carbide (WC) or graded film which is a metal compound coating of tantalum carbide (TaC) It may be formed by a plating method.

  In addition, a coating having a thickness of 0.02 to 0.2 [mu] m, preferably 0.05 to 0.1 [mu] m is dry-plated as a base layer on the surface of a decorative substrate made of a metal other than copper and copper alloy or ceramics. It is formed by the method.

  Further, a nickel coating having a thickness of 1 to 10 μm is formed as a base layer on the surface of a decorative article made of copper and a copper alloy by a wet plating method, and amorphous nickel having a thickness of 3 to 10 μm is formed on the surface of the nickel coating. The phosphorus alloy film may be formed by a wet plating method.

  Further, on the surface of the base material for decorative articles made of copper or copper alloy, the base layer is at least selected from the group consisting of copper, palladium, copper-tin alloy, copper-tin-zinc alloy and copper-tin-palladium alloy. A single film having a thickness of 2 to 9 μm may be formed by a wet plating method.

  The method for manufacturing a decorative article having a white coating according to the present invention includes titanium carbide that forms the titanium carbide layer and platinum or platinum that forms the decorative coating layer between the titanium carbide layer and the decorative coating layer. A mixed layer made of an alloy and having a thickness of 0.005 to 0.04 μm is formed by a dry plating method.

Further, a stainless steel coating layer having a thickness of 0.05 to 1.5 μm may be formed between the titanium carbide layer and the decorative coating layer by a dry plating method.
The stainless steel coating layer comprises carbon 0.01-0.12% by volume, silicon 0.1-1.5% by volume, manganese 1.0-2.5% by volume, nickel 8-22% by volume, chromium 15- A film made of austenitic stainless steel having a composition of 26% by volume and the balance being iron is formed by at least one of sputtering, ion plating and arc methods.

  The method for producing a decorative article having a white coating according to the present invention includes at least one of the underlayer, the titanium carbide layer, the mixed layer, and the decorative coating layer in a sputtering method, an ion plating method, and an arc method. It is formed by one method.

  Further, the titanium carbide layer and / or the mixed layer may be formed by a dry plating method using methane gas.

  The method for producing a decorative article having a white coating according to the present invention comprises forming at least one coating different from the color tone of the decorative coating layer on a part of the surface of the decorative coating layer by a dry plating method or a wet plating method. Features.

  The coating film having a color tone different from that of the decorative coating layer is a decorative coating layer made of an alloy containing no nickel, and is preferably formed by a dry plating method or a wet plating method.

  The coating film having a color tone different from that of the decorative coating layer may be made of gold, gold alloy, titanium nitride, zirconium nitride, hafnium nitride, or diamond-like carbon (DLC).

  In addition, as a coating having a color tone different from that of the decorative coating layer, a coating having a two-layer structure including a lower layer made of titanium nitride, zirconium nitride or hafnium nitride and an upper layer made of gold or a gold alloy may be formed.

  Further, a titanium film may be formed between the decorative film layer and a diamond-like carbon (DLC) film that is a film having a color tone different from that of the decorative film layer, and a silicon film may be formed on the titanium film surface. good.

  The method for producing a decorative article having a white coating according to the present invention is characterized in that the decorative coating layer is a mixed layer composed of titanium carbide forming a titanium carbide layer and platinum or a platinum alloy.

  The method for producing a decorative article having a white coating according to the present invention is characterized in that the decorative coating layer has a surface hardness (Hv: micro Vickers hardness meter, 5 g load) of 1000 to 2000.

  The method for manufacturing a decorative article having a white coating according to the present invention is characterized in that the decorative article is a watch exterior part.

  According to the present invention, a color tone peculiar to platinum or a platinum alloy film can be obtained. Therefore, it has a high-class feeling, is hard and does not easily deteriorate in appearance quality due to dents or scratches, and has a high-quality feeling at a relatively low cost. A decorative article having a certain white coating and a method for producing the same can be provided.

  In addition, if a stainless steel coating layer is formed between the titanium carbide layer and the decorative coating layer, if a problem such as color unevenness occurs in the platinum or platinum alloy coating, the substrate for decorative products, the base layer, and the carbonized layer The platinum or platinum alloy coating can be peeled off using aqua regia without attacking the titanium layer, and after the peeling, it can be regenerated by forming a platinum coating or platinum alloy coating on the surface of the stainless steel coating layer again. Decorative article and a method for manufacturing the same can be provided.

  Hereinafter, a decorative article having a white coating according to the present invention and a manufacturing method thereof will be described in detail.

  A decorative article having a white coating according to the present invention is composed of a decorative article substrate, a base layer, preferably a base layer not containing nickel, a titanium carbide layer, and a decorative coating layer. Furthermore, a stainless steel coating layer formed by a dry plating method may be provided between the titanium carbide layer and the decorative coating layer. The decorative article having a white coating according to the present invention may have at least one coating different from the color tone of the coating layer on a part of the surface of the white coating that is the decorative coating layer.

[Base material for decorative products]
The base material for ornament used in the ornament having a white film according to the present invention is a substrate formed from metal or ceramics.
Specific examples of the metals (including alloys) include stainless steel, titanium, titanium alloys, copper, copper alloys, and tungsten. These metals can be used alone or in combination
It can be used in combination of more than one species.

Specific examples of the ceramics include zirconia ceramics. This zirconia ceramic is a stabilized zirconia having a composition of 3 to 7% by weight of yttrium oxide (Y ₂ O ₂ ) or another stabilizer (for example, magnesium oxide (MgO), calcium oxide (CaO)), and has a white color tone. Presents. More specifically, this zirconia ceramic is composed mainly of zirconia and a binder, and 20 to 25 binders with respect to 100 parts by weight of stabilized zirconia powder containing 3 to 7% by weight of a stabilizer such as yttrium oxide. It contains parts by weight and exhibits a white color tone after firing. As the binder, for example, a mixture of at least two selected from polyethylene, polypropylene, polystyrene, ethylene vinyl acetate, butyl methacrylate, polyacetal, wax and stearic acid is preferable.

  In the present invention, the reason for selecting zirconia ceramics containing 3 to 7% by weight of a stabilizer such as yttrium oxide (yttria) is that if the stabilizer such as yttria is less than 3% by weight, the impact resistance of the molded zirconia ceramics The resistance decreases (becomes brittle), and it is easy for cracks to occur due to external impact, and even if the stabilizer exceeds 7% by weight, impact resistance decreases, and cracks occur due to external impact. It is because it becomes easy to generate | occur | produce. When the stabilizer is within the above range, the crystal structure of zirconia ceramics is a two-phase mixed structure of cubic and monoclinic crystals, so that the impact resistance is considered to be stable.

  In addition, the binder content is set to 20 to 25 parts by weight with respect to 100 parts by weight of zirconia powder. When the binder is less than 20 parts by weight, the injection molding becomes worse and the material is completely filled in the mold. This is because if the amount is more than 25 parts by weight, the degreasing process takes time and the mass productivity is deteriorated, and the molded shape is easily broken.

The base material for decorative articles made of metal is prepared from the above-described metal by conventionally known machining.
Further, the decorative article base material is subjected to at least one surface finish among a mirror surface, a satin finish, a hairline pattern, a honing pattern, a stamping pattern, and an etching pattern by various means as required.

  Further, a decorative article base material made of ceramics, for example, a watch case base material, is made by forming a molded article having a watch case shape by injection molding using a material mainly composed of zirconia and a binder. It is manufactured by roughing by machining, and further, degreasing and firing the roughened molded body to make a rough base material for a watch case, and then machining the rough base material by grinding and polishing. .

  Examples of ornaments (including parts) in the present invention include watch case parts, watch bands, wristwatch crowns, watch exterior parts such as wristwatch back covers, belt buckles, rings, necklaces, bracelets, earrings, pendants, Examples include brooches, cufflinks, tie stoppers, badges, medals, eyeglass frames, camera bodies, and door knobs.

  In the present invention, it is preferable to wash and degrease the surface of the decorative article substrate in advance with a conventionally known organic solvent or the like before forming the base layer on the surface of the decorative article substrate.

[Underlayer]
The underlayer constituting the decorative article having a white coating according to the present invention is composed of at least one plating coating formed by a wet plating method and / or a dry plating method.

  When the base material for decoration is made of a metal other than copper and copper alloy, or ceramics, the underlying layer formed on the surface of the base material is titanium (Ti) or chromium (Cr) formed by a dry plating method. A metal coating made of zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), or tantalum (Ta) is desirable.

The underlayer is formed by dry plating, and has a carbon atom content of 5 to 15 atomic% titanium carbide (TiC), chromium carbide (Cr ₃ C ₂ ), zirconium carbide (ZrC), hafnium carbide (HfC), A metal compound film made of vanadium carbide (VC), niobium carbide (NbC), tungsten carbide (WC) or tantalum carbide (TaC) is particularly preferable. In this metal compound film, the carbon atom content of the metal compound gradually decreases as it approaches the surface of the decorative substrate, and this metal compound film is called a so-called gradient film.

  The thickness of these metal coating and metal compound coating (underlayer) is preferably 0.02 to 0.2 μm, and particularly preferably 0.05 to 0.1 μm.

  Specific examples of the dry plating method include a sputtering method, an arc method, an ion plating method, a physical vapor deposition method (PVD) such as an ion beam, and CVD. Of these, the sputtering method, the arc method, and the ion plating method are particularly preferably used.

  Moreover, in the decorative article having a white coating according to the present invention, when the decorative article base material is made of copper or a copper alloy, the base layer has a thickness of 1 to 10 μm formed on the surface of the base material by a wet plating method, Preferably, it is composed of a nickel film having a thickness of 1 to 5 μm and an amorphous nickel-phosphorus alloy film having a thickness of 3 to 10 μm, preferably 3 to 5 μm, formed on the surface of the nickel film by a wet plating method.

  From the viewpoint of preventing nickel allergy, when the decorative article base is made of copper or a copper alloy, the base layer is formed by wet plating, copper, palladium, copper-tin alloy, copper-tin- It is preferable that the coating film is made of at least one of a zinc alloy and a copper-tin-palladium alloy and has a thickness of 2 to 9 μm, preferably 2 to 3 μm.

  Further, these metal compound films may be alloys other than the above, which are formed by dry plating or wet plating, and do not contain nickel.

[Titanium carbide layer]
The titanium carbide layer constituting the decorative article having the white coating according to the present invention is formed by a dry plating method. Specific examples of the dry plating method include a sputtering method, an arc method, an ion plating method, a physical vapor deposition method (PVD) such as an ion beam, and CVD. Of these, the sputtering method, the arc method, and the ion plating method are particularly preferably used.
The thickness of the titanium carbide layer is 0.2 to 1.5 μm, preferably 0.5 to 1.0 μm.

[Stainless steel coating layer]
The stainless steel coating layer that may constitute a decorative article having a white coating according to the present invention is formed between the titanium carbide layer and the decorative coating layer so that the decorative article can be reproduced. is there. That is, when there is a problem in the formation of the decorative coating layer (when the decorative coating is uneven), aqua regia is used for peeling the decorative coating layer. The layer, the underlayer, and the surface of the decorative article base were attacked, and the decorative article could not be regenerated. The coating layer provided to solve this problem is a stainless steel coating layer, and even if the decorative coating layer is peeled off with aqua regia, the stainless steel coating layer allows the titanium carbide layer, the underlayer, and the decorative substrate surface to Will not be attacked. Therefore, after the decorative coating layer in which the problem has occurred is peeled off using aqua regia, the decorative article can be regenerated by forming the decorative coating layer on the surface of the stainless steel coating again.

  The stainless steel coating layer is formed by sputtering, which is a dry plating method, so that the thickness of the stainless steel coating layer is in the range of 0.05 to 1.5 μm. The composition of the stainless steel coating layer is as follows: carbon 0.01-0.12% by volume, silicon 0.1-1.5% by volume, manganese 1.0-2.5% by volume, nickel 8-22% by volume, Austenitic stainless steel made of 15 to 26% by volume of chromium and the balance being iron is preferable.

[Decorative coating layer]
The decorative coating layer which is the outermost layer constituting the decorative article having the white coating according to the present invention is a dry plating method on the surface of the titanium carbide layer formed on the surface of the underlayer by the dry plating method or the surface of the mixed layer described later. It consists of a precious metal platinum or platinum alloy coating formed by Specific examples of the dry plating method include a sputtering method, an arc method, an ion plating method, a physical vapor deposition method (PVD) such as an ion beam, and CVD. Of these, the sputtering method, the arc method, and the ion plating method are particularly preferably used.

  In addition, in the decorative article having a white coating according to the present invention, a mixed layer (a mixed layer made of titanium carbide and platinum or a platinum alloy forming a titanium carbide layer) described later can be used as a decorative coating layer.

  The thickness of the decorative coating layer is 0.02 to 0.1 μm, preferably 0.03 to 0.06 μm.

  In addition, as said alloy used for formation of a decorative coating layer, the alloy which does not contain nickel formed by the dry-type plating method or the wet-plating method is preferable.

(Mixed layer)
In the decorative article having a white coating according to the present invention, the mixed layer may be formed between the titanium carbide layer and the decorative coating layer as necessary, and is a coating formed by a dry plating method. Specific examples of the dry plating method include a sputtering method, an arc method, an ion plating method, a physical vapor deposition method (PVD) such as an ion beam, and CVD. Of these, the sputtering method, the arc method, and the ion plating method are particularly preferably used.

  This coating consists of titanium carbide forming a titanium carbide layer and platinum or a platinum alloy forming a decorative coating layer. The thickness of the mixed layer is usually 0.005 to 0.04 μm, preferably 0.008 to 0.03 μm. By providing such a mixed layer, the adhesion between the titanium carbide layer and the decorative coating layer can be further strengthened.

  The color evaluation by the L *, a *, b * display system (CIE surface system) composed of the titanium carbide layer and the decorative coating layer, or the titanium carbide layer, the mixed layer, and the decorative coating layer is 85 <L *. It is desirable that <95, 1.5 <a * <4.0, 4.5 <b * <6.5. Among these, it is preferable that 88 <L * <92, 1.8 <a * <2.5, and 5.0 <b * <5.5.

In addition, each of the decorative coating layer formed on the base material for decorative articles subjected to the mirror finish and the decorative coating layer formed on the base material for decorative articles subjected to the hairline finish (fine line pattern) Color evaluation by L *, a *, b * display system (CIE table system)
85 <L * <90, 0 <a * <2.0, 3.5 <b * <5.0,
75 <L * <85, 0 <a * <2.0, 3.5 <b * <5.0.
In addition, the Δ values of L *, a *, and b * of the decorative coating layer formed on the decorative article base material with various surface finishes are ΔL * = ± 6.0, Δa * = ± 1. 55, Δb * = ± 2.25.

  Further, the surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the surface layer composed of the titanium carbide layer and the decorative coating layer or the titanium carbide layer, the mixed layer and the decorative coating layer is usually 700 to 2000, preferably 1000 to 2000.

  In a decorative article having a white coating according to the present invention, at least a titanium carbide coating layer having a thickness of 0.5 to 1.0 μm and a decorative coating layer having a thickness of 0.03 to 0.06 μm are formed on the surface of the base layer. As a result, it is possible to obtain a decorative article having a high-quality white coating that is unlikely to deteriorate in appearance quality due to scratches or the like.

  The mixed layer is preferably an alloy containing no nickel.

[Coating different from decorative coating layer]
In the decorative article having a white coating according to the present invention, at least one coating different from the color tone of the decorative coating layer is formed on a part of the surface of the white coating having a platinum color tone or a platinum alloy color tone composed of the decorative coating layer. It may be formed by a wet plating method.

  As the coating different from the color tone of the decorative coating layer, a coating made of gold, gold alloy (preferably a gold alloy not containing nickel), titanium nitride, zirconium nitride, hafnium nitride or diamond-like carbon (DLC) is desirable. This coating appears in the appearance of the decorative article together with the outermost layer forming the decorative coating layer. Therefore, the ornament according to the present invention includes so-called two-tone ornaments.

  The thickness of the plated coating having a color tone different from that of the decorative coating layer is usually 0.1 to 1.0 μm, preferably 0.2 to 0.5 μm.

  The decorative coating layer has a color tone different from that of a lower layer made of titanium nitride, zirconium nitride or hafnium nitride, and an upper layer made of gold or a gold alloy (preferably a gold alloy not containing nickel) (for example, a gold-iron alloy). It may be a two-layer structure. In this case, the thickness of the lower layer is usually 0.2 to 1.5 μm, preferably 0.5 to 1.0 μm, and the thickness of the upper layer is usually 0.03 to 0.2 μm, preferably 0.05 to 0. .1 μm.

  Further, the coating film having a color tone different from that of the decorative coating layer includes a lower layer made of titanium, an intermediate layer made of titanium nitride, zirconium nitride, or hafnium nitride, and an upper layer made of gold or a gold alloy (preferably a gold alloy not containing nickel). It may be a three-layer structure. In this case, the thickness of the lower layer is usually 0.02 to 0.1 μm, preferably 0.03 to 0.08 μm, and the thickness of the intermediate layer is usually 0.2 to 1.5 μm, preferably 0.5 to It is 1.0 micrometer, and the thickness of an upper layer is 0.03-0.2 micrometer normally, Preferably it is 0.05-0.1 micrometer.

  Furthermore, in the coating film having a color tone different from that of the decorative coating layer, a titanium coating, a silicon coating, and a diamond-like carbon (DLC) coating may be formed in this order on part of the surface of the decorative coating layer. In this case, the thickness of the lower layer is usually 0.05 to 0.3 μm, preferably 0.08 to 0.2 μm, and the thickness of the intermediate layer is usually 0.05 to 0.3 μm, preferably 0.08 to The thickness of the upper layer is usually 0.5 to 3.0 μm, preferably 0.8 to 1.5 μm.

Each layer constituting the single-layer structure, the two-layer structure, or the three-layer structure is usually formed by a dry plating method. Specific examples of the dry plating method include a sputtering method, an arc method, an ion plating method, a physical vapor deposition method (PVD) such as an ion beam, and CVD. Of these, the sputtering method, the arc method, and the ion plating method are particularly preferably used.

  The decorative film layer has a color tone different from that of the lower layer made of a gold strike plating film formed by a wet plating method and a gold or gold alloy plating film (preferably not containing nickel) formed by a wet plating method. It may be a two-layer structure with an upper layer made of a gold alloy plating film) or the like. In this case, the thickness of the lower layer is usually 0.05 to 0.2 μm, preferably 0.05 to 0.1 μm, and the thickness of the upper layer is usually 1.0 to 10 μm, preferably 1.0 to 3.0 μm. It is.

  Such a decorative article having a coating having a color tone different from that of the decorative coating layer on a part of the surface of the decorative coating layer can be prepared, for example, by the following method.

  First, a base layer is formed on the surface of a base material for a decorative article, and after the decorative coating layer is formed on the surface of the base layer, a masking process is performed on a part of the surface of the decorative coating layer. A plating film having a color tone different from that of the decorative coating layer is formed on the surface by a dry plating method or a wet plating method, and then the process of removing the mask and the plating film on the mask is performed at least once to obtain a platinum color or platinum color. A decorative coating layer having two or more color tones, which is composed of a white coating film having an alloy color tone and at least one plated coating film having a color tone different from that of the white coating film, can be obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by these Examples.

Example 1
First, a watch case base material and a watch band base material, which are decorative articles obtained by machining stainless steel (SUS316L), were washed and degreased with an organic solvent. The surfaces of these base materials were mirror finished by machining.

  Next, these substrates were mounted in an ion plating apparatus, and the substrate surface was bombard cleaned in an argon atmosphere.

Next, a titanium plating film (underlayer) having a thickness of 0.05 μm was formed on the surface of these base materials by the ion plating method (hot cathode method) under the following film forming conditions.
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 200-500 mA
Gas: Argon gas Film forming pressure: 0.004 to 0.009 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 50V
Filament voltage: 7V

Next, a titanium carbide plating film (titanium carbide layer) having a white color tone with a thickness of 0.6 μm is formed on the surface of the titanium plating film formed on the surface of the substrate by the ion plating method (hot cathode method) as described below. Formed under conditions.
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 300 mA
Gas: Methane gas deposition pressure: 0.02 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 60V
Filament voltage: 7V

Subsequently, a mixed plating film (mixed layer) of titanium carbide and platinum having a white color tone with a thickness of 0.02 μm is formed on the surface of the titanium carbide plating film formed on the surface of these substrates by an ion plating method (hot cathode method). Was formed under the following film forming conditions.
<Film formation conditions>
Evaporation source: titanium, platinum electron gun: 10 kV, 300 mA (evaporation source: titanium)
: 10 kV, 500 mA (evaporation source: platinum)
Gas: Methane gas deposition pressure: 0.02 Pa
Acceleration voltage (bias voltage): Ground to -50V
Anode voltage: 60V
Filament voltage: 7V

Next, a platinum coating (decoration coating layer) having a thickness of 0.05 μm in white color is formed on the surface of the mixed plating coating of titanium carbide and platinum formed on the surface of these substrates by an ion plating method (hot cathode method). A platinum-colored watch case and watch band were obtained under the following film forming conditions.
<Film formation conditions>
Evaporation source: Platinum electron gun: 10 kV, 500 mA
Gas: Argon gas Film forming pressure: 0.2 Pa
Acceleration voltage (bias voltage): Ground to -50V
Anode voltage: 60V
Filament voltage: 7V

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum coating formed on the surfaces of the watch case and watch band obtained as described above was 1400. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

(Example 2)
First, a watch case base material and a watch band base material, which are decorative articles obtained by machining titanium, were washed and degreased with an organic solvent. The surfaces of these base materials were mirror finished by machining.

  Subsequently, these base materials were attached in a sputtering apparatus, and the surface of the base material was bombard cleaned in an argon atmosphere.

Subsequently, a zirconium film (underlayer) having a thickness of 0.05 μm was formed on the surface of these base materials by a sputtering method (magnetron sputtering method) under the following film forming conditions.
<Film formation conditions>
Target: Zirconium sputtering gas: Argon gas Deposition pressure: 0.5 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a titanium carbide plating film (titanium carbide layer) having a white color tone with a thickness of 0.6 μm is formed on the surface of the zirconium plating film formed on the surface of the base material by a sputtering method (magnetron sputtering method) under the following film formation conditions. Formed.
<Film formation conditions>
Target: Titanium sputtering gas: Methane gas Deposition pressure: 0.6 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a stainless steel plating film (stainless steel coating layer) having a white color tone with a thickness of 0.2 μm is formed on the surface of the titanium carbide plating film formed on the surface of the substrate by the sputtering method (magnetron sputtering method) as described below. Formed under conditions.
<Film formation conditions>
Target: Austenitic stainless steel SUS304
Sputtering gas: Argon gas Film forming pressure: 0.2 to 0.9 Pa
Target applied power: 0.4 to 0.5 kW
Bias voltage (acceleration voltage): Ground to -300V

Next, a platinum coating (decoration coating layer) having a white color tone with a thickness of 0.05 μm is formed on the surface of the stainless steel plating coating formed on the surface of the base material by the sputtering method (magnetron sputtering method) under the following film forming conditions. As a result, a platinum-colored watch case and watch band were obtained.
<Film formation conditions>
Target: Platinum sputtering gas: Argon gas Deposition pressure: 0.2 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum coating formed on the surfaces of the watch case and watch band obtained as described above was 1300. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

(Example 3)
First, a watch case base material and a watch band base material, which are decorative articles obtained by machining brass (copper alloy), were washed and degreased with an organic solvent. The surfaces of these base materials were mirror finished by machining.

Next, these substrates are immersed in a plating solution having the following composition, and electroplated under the following plating conditions to form a 2 μm thick copper-tin alloy plating film (underlayer 1) on the substrate surface. , Washed with water.
<Copper-tin alloy plating>
<Composition of plating solution>
Copper cyanide 15g / l (in terms of copper)
Sodium stannate 15g / l (tin equivalent)
Zinc cyanide 1g / l (Zinc conversion)
KOH 20g / l
KCN (free) 30g / l
Brightener 10ml / l
<Plating conditions>
pH 12.5 (at 50 ° C)
Liquid temperature 50 ℃
Current density (Dk) 2A / dm ²
Deposition rate 3 min / 1 μm

Next, the substrate having these copper-tin alloy plating films is dipped in a plating solution having the following composition, electroplated under the following plating conditions, and a 2 μm thick copper-tin-zinc alloy plating film (underlayer) 2) was formed on the surface of the copper-tin alloy plating film and washed with water.
<Copper-tin-zinc alloy plating>
<Composition of plating solution>
Copper cyanide 8.5g / l (in terms of copper)
Sodium stannate 34.0g / l (tin equivalent)
Zinc cyanide 1g / l (Zinc conversion)
KOH 20g / l
KCN (free) 50g / l
Brightener 1 5ml / l
Brightener 2 5ml / l
<Plating conditions>
pH 13.0 (at 50 ° C)
Liquid temperature 60 ℃
Current density (Dk) 2A / dm ²
Deposition rate 3 min / 1 μm

Next, a substrate having these copper-tin-zinc alloy plating films is dipped in a plating solution having the following composition and electroplated under the following plating conditions to form a palladium strike plating film (underlayer) having a thickness of 0.5 μm. 3) was formed on the surface of the copper-tin-zinc alloy plating film and washed with water.
<Palladium strike plating>
<Composition of plating solution>
Pure palladium 1-3g / l
<Plating conditions>
pH 8
Liquid temperature 32 ℃
Current density (Dk) 3-5 A / dm ²
Time 30 seconds

Subsequently, these base materials were attached in a sputtering apparatus, and the surface of the base material was bombard cleaned in an argon atmosphere.

Next, a 0.05-μm-thick tantalum film (underlayer 4) was formed on the surface of the palladium strike plating film formed on the surface of the base material by the sputtering method (magnetron sputtering method) under the following film formation conditions.
<Film formation conditions>
Target: Tantalum sputtering gas: Argon gas Deposition pressure: 0.4 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a titanium carbide plating film (titanium carbide coating layer) having a white color tone with a thickness of 0.6 μm is formed on the surface of the tantalum plating film formed on the surface of the base material by sputtering (magnetron sputtering method) as follows. Formed with.
<Film formation conditions>
Target: Titanium sputtering gas: Mixed gas of methane gas and argon gas Film forming pressure: 0.6 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a platinum alloy coating (decoration coating layer) having a thickness of 0.05 μm in white color is formed on the surface of the titanium carbide plating coating formed on the surface of the base material by the sputtering method (magnetron sputtering method) under the following film formation conditions. A platinum-colored watch case and a watch band were formed.
<Film formation conditions>
Target: Platinum alloy sputtering gas: Argon gas Deposition pressure: 0.6 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum alloy coating formed on the surface of the watch case and watch band obtained as described above was 1300. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film color tone and a high-quality white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

Example 4
First, a wristwatch case base material and a wristwatch band base material obtained by performing molding or the like on the shape of a wristwatch case and a wristwatch band, which are decorative articles manufactured using zirconia ceramics, were washed and degreased with an organic solvent ( (The manufacturing method of these base materials, for example, a watch case is described more specifically in the specification related to Japanese Patent Application No. 2001-333236, filed on October 30, 2001 by the applicant of the present application). . The surfaces of these base materials were mirror finished by machining.

Subsequently, these base materials were attached in a sputtering apparatus, and the surface of the base material was bombard cleaned in an argon atmosphere.

Next, a chromium plating film (underlayer) having a thickness of 0.05 μm was formed on these substrate surfaces by sputtering (magnetron sputtering) under the following film formation conditions.
<Film formation conditions>
Target: Chromium sputtering gas: Argon gas Deposition pressure: 0.4 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a titanium carbide plating film (titanium carbide layer) having a white color tone with a thickness of 0.6 μm is formed on the surface of the chromium plating film formed on the surface of the base material by sputtering (magnetron sputtering) under the following film formation conditions. Formed.
<Film formation conditions>
Target: Titanium sputtering gas: Methane gas Deposition pressure: 0.6Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a stainless steel plating film (stainless steel coating layer) having a white color tone with a thickness of 0.2 μm is formed on the surface of the titanium carbide plating film formed on the surface of the substrate by the sputtering method (magnetron sputtering method) as described below. Formed under conditions.
<Film formation conditions>
Target: Austenitic stainless steel (SUS304)
Sputtering gas: Argon gas Film forming pressure: 0.2 to 0.9 Pa
Target applied power: 0.4 to 0.5 kW
Bias voltage (acceleration voltage): Ground to -300V

Next, a platinum coating (decoration coating layer) having a white color tone with a thickness of 0.05 μm is formed on the surface of the stainless steel plating coating formed on the surface of the base material by the sputtering method (magnetron sputtering method) under the following film forming conditions. As a result, a platinum-colored watch case and watch band were obtained.
<Film formation conditions>
Evaporation source: Platinum gas: Argon gas Deposition pressure: 0.2 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum coating formed on the surfaces of the watch case and watch band obtained as described above was 1300. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

(Example 5)
First, a watch case base material and a watch band base material, which are decorative articles obtained by machining stainless steel (SUS316L), were washed and degreased with an organic solvent. The surfaces of these base materials were mirror finished by machining.

  Next, these substrates were mounted in an ion plating apparatus, and the substrate surface was bombard cleaned in an argon atmosphere.

Next, a titanium plating film (underlayer) having a thickness of 0.05 μm was formed on the surface of these base materials by the ion plating method (hot cathode method) under the following film forming conditions.
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 200-500 mA
Gas: Argon gas Film forming pressure: 0.004 to 0.009 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 50V
Filament voltage: 7V

Next, a titanium carbide plating film (titanium carbide layer) having a white color tone with a thickness of 0.6 μm is formed on the surface of the titanium plating film formed on the surface of the substrate by the ion plating method (hot cathode method) as described below. Formed under conditions.
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 300 mA
Gas: Mixed gas of methane gas and argon gas Film forming pressure: 0.02 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 60V
Filament voltage: 7V

Next, a platinum coating (decoration coating layer) having a thickness of 0.05 μm on the surface of the titanium carbide plating coating formed on the surface of these base materials is subjected to the following deposition conditions by an ion plating method (hot cathode method). A platinum-colored watch case and watch band were obtained.
<Film formation conditions>
Evaporation source: Platinum electron gun: 10 kV, 500 mA
Gas: Argon gas Film forming pressure: 0.2 Pa
Acceleration voltage (bias voltage): Ground to -50V
Anode voltage: 60V
Filament voltage: 7V

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum coating formed on the surfaces of the watch case and watch band obtained as described above was 1200. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

(Example 6)
A plating film different from the color tone of this coating film was formed on a part of the surface of the platinum coating film (decorative coating layer) obtained in the same manner as in Example 5 by the dry plating method.

That is, a titanium plating film having a thickness of 0.05 μm was formed on the surface of the film by the ion plating method (hot cathode method) under the following film forming conditions.
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 200-500 mA
Gas: Argon gas Film forming pressure: 0.2 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 40-50V
Filament voltage: 7V

Next, a titanium nitride plating film exhibiting a gold color with a thickness of 0.6 μm was formed on the surface of the titanium plating film by the ion plating method (hot cathode method) under the following film forming conditions.
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 200-500 mA
Gas: Mixed gas of argon gas and nitrogen gas Film forming pressure: 0.2 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 40-50V
Filament voltage: 7V

Next, a gold-iron alloy plating film having a gold color with a thickness of 0.1 μm was formed on the surface of the titanium nitride plating film by the ion plating method (hot cathode method) under the following film forming conditions.
<Film formation conditions>
Evaporation source: gold-iron alloy electron gun: 8 kV, 500 mA
Gas: Argon gas Film forming pressure: 0.26 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 10-30V
Filament voltage: 7V

  Next, a part of the surface of the gold-iron alloy plating film is masked (using an epoxy resist as a mask material), and the gold-iron alloy plating film, titanium nitride plating film and titanium plating film are sequentially removed with an etching solution. Finally, the mask was removed to obtain a watch case and a watch band having a decorative coating layer having two different tones, consisting of a platinum-colored coating and a gold-colored gold-iron alloy plating coating.

  In addition, as a stripping solution for a gold-iron alloy plating film, a stripping solution containing cyan as a main component and containing an oxidizing agent is used. As a stripping solution for a titanium nitride plating film and a titanium plating film, ammonium fluoride is used as a main component. Was used, and methylene chloride was used as a mask remover.

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum film formed on the surface of the watch case and watch band obtained as described above is 1200, and gold-iron The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the alloy plating film was 120. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

(Example 7)
A plating film different from the color tone of this coating film was formed on a part of the surface of the platinum coating film (decorative coating layer) obtained in the same manner as in Example 5 by the wet plating method.

  That is, the substrate on which this film was formed was cleaned by performing electrolytic degreasing, neutralization, and water washing as pretreatment.

Next, the substrate having this film was immersed in a plating solution having the following composition, and electroplated under the following plating conditions to form a gold strike plating film having a thickness of 0.1 μm on the substrate surface and washed with water.
《Gold strike plating》
<Composition of plating solution>
Gold 3-5g / l
Sulfuric acid 10g / l
<Plating conditions>
pH 0.3 to less than 1 Liquid temperature 25 ° C
Current density (Dk) 3-5 A / dm ²
Time 30 seconds

Next, the substrate having the gold strike plating film is immersed in a plating solution having the following composition and electroplated under the following plating conditions to form a gold-iron alloy plating film having a thickness of 2.0 μm on the surface of the gold strike plating film. And washed with water.
《Gold-iron alloy plating》
<Composition of plating solution>
Potassium cyanide 8.7 g / l (metal 5.0 g / l)
Iron chloride 2.7g / l (metal 1.0g / l)
Citric acid 150 g / l or more Sodium citrate 150 g / l or more Brightener 10 ml / l
<Plating conditions>
pH 3.5-3.7
Bath temperature 37-40 ° C
Current density (Dk) 1.0 to 1.5 A / dm ²
Be (Baume specific gravity) 20

  Next, a part of the surface of the gold-iron alloy plating film is subjected to a masking process, the gold-iron alloy plating film and the gold strike plating film are sequentially removed with an etching solution, and finally the mask is removed to thereby obtain a platen color tone. A watch case and a watch band having two decorative coating layers of different colors, each consisting of a coating and a golden gold-iron alloy plating coating, were obtained.

  In addition, as a stripping solution for gold-iron alloy plating coating and gold strike plating coating, a stripping solution containing cyan as a main component and an oxidizing agent was used, and methylene chloride was used as a mask stripping solution.

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum coating formed on the surface of the watch case and watch band obtained as described above is 1100, and the gold-iron composite The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the gold plating film was 120. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

(Example 8)
A plating film different from the color tone of this coating film was formed on a part of the surface of the platinum coating film (decorative coating layer) obtained in the same manner as in Example 5 by the dry plating method.

That is, after a mask material (epoxy resist) is applied to a part of the coating surface and dried, a 0.05 μm-thick titanium plating coating is applied to the coating surface and the mask material surface by a sputtering method (magnetron sputtering method) as follows. The film was formed under the following film forming conditions.
<Film formation conditions>
Target: Titanium sputtering gas: Argon gas Deposition pressure: 0.02 Pa
Target applied power: 0.3 to 0.5 kW
Bias voltage (acceleration voltage): -50 to -100V

Next, a silicon plating film having a thickness of 0.1 μm was formed on the surface of the titanium plating film by a sputtering method (magnetron sputtering method) under the following film forming conditions.
<Film formation conditions>
Target: Silicon sputtering gas: Argon gas Film forming pressure: 0.05 Pa
Target applied power: 0.3 to 0.5 kW
Bias voltage (acceleration voltage): -50 to -100V

Next, a black diamond-like carbon (DLC) plating film having a thickness of 0.1 μm was formed on the surface of the silicon plating film by plasma CVD (Chemical Vapor Deposition) under the following film formation conditions.
<Film formation conditions>
Gas: Benzene deposition pressure: 0.2 Pa
Filament current: 20A
Anode current: 2.0A
Cathode voltage (acceleration voltage): -1.0 to -5.0 kV
Next, the masking material is etched with methylene chloride, and the titanium plating film, the silicon plating film and the DLC film formed immediately above the masking material are lifted off to form a platinum-colored film and a black DLC plating film. A watch case and a watch band having decorative coating layers of three different colors were obtained.

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum film formed on the surface of the watch case and the watch band obtained as described above is 1200, and the DLC plating film The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) was 1800. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

Example 9
First, a watch case base material and a watch band base material, which are decorative articles obtained by machining titanium, were washed and degreased with an organic solvent. The surfaces of these base materials were mirror finished by machining.

  Subsequently, these base materials were attached in a sputtering apparatus, and the surface of the base material was bombard cleaned in an argon atmosphere.

Subsequently, a zirconium film (underlayer) having a thickness of 0.05 μm was formed on the surface of these base materials by a sputtering method (magnetron sputtering method) under the following film forming conditions.
<Film formation conditions>
Target: Zirconium sputtering gas: Argon gas Deposition pressure: 0.5 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a titanium carbide plating film (titanium carbide layer) having a white color tone with a thickness of 0.6 μm is formed on the surface of the zirconium plating film formed on the surface of the base material by a sputtering method (magnetron sputtering method) under the following film formation conditions. Formed.
<Film formation conditions>
Target: Titanium sputtering gas: Mixed gas of methane gas and argon gas Film forming pressure: 0.6 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

Next, a stainless steel plating film (stainless steel coating layer) having a white color tone with a thickness of 0.2 μm is formed on the surface of the titanium carbide plating film formed on the surface of the substrate by the sputtering method (magnetron sputtering method) as described below. Formed under conditions.
<Film formation conditions>
Target: Austenitic stainless steel SUS304
Sputtering gas: Argon gas Film forming pressure: 0.2 to 0.9 Pa
Target applied power: 0.4 to 0.5 kW
Bias voltage (acceleration voltage): Ground to -300V

Next, a platinum coating (decoration coating layer) having a white color tone with a thickness of 0.05 μm is formed on the surface of the stainless steel plating coating formed on the surface of the base material by the sputtering method (magnetron sputtering method) under the following film forming conditions. As a result, a platinum-colored watch case and watch band were obtained.
<Film formation conditions>
Target: Platinum sputtering gas: Argon gas Deposition pressure: 0.2 Pa
Target applied power: 0.5 kW
Bias voltage (acceleration voltage): -50V

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum coating formed on the surfaces of the watch case and watch band obtained as described above was 1300. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

(Example 10)
First, a watch case base material and a watch band base material, which are decorative articles obtained by machining stainless steel (SUS316L), were washed and degreased with an organic solvent. The surfaces of these base materials were mirror finished by machining.

  Next, these substrates were mounted in an ion plating apparatus, and the substrate surface was bombard cleaned in an argon atmosphere.

Subsequently, a titanium carbide plating film (underlayer) having a gradient structure with a carbon atom content of 5 to 15 atom% having a thickness of 0.05 μm is applied to the surface of these base materials by an ion plating method (hot cathode method) as follows. It formed on film-forming conditions.
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 200-500 mA
Gas: Mixed gas of argon gas and methane gas Film forming pressure: 0.004 to 0.009 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 50V
Filament voltage: 7V

Next, a titanium carbide plating film (titanium carbide layer) having a white color tone with a thickness of 0.6 μm and a carbon atom content of 40 ± 10 atomic% is formed on the surface of the titanium carbide plating film formed on the surface of these base materials. The film was formed under the following film forming conditions by an ion plating method (hot cathode method).
<Film formation conditions>
Evaporation source: Titanium electron gun: 10 kV, 300 mA
Gas: Mixed gas of methane gas and argon gas Film forming pressure: 0.02 Pa
Acceleration voltage (bias voltage): Ground to -100V
Anode voltage: 60V
Filament voltage: 7V

Next, a platinum coating (decoration coating layer) having a thickness of 0.05 μm on the surface of the titanium carbide plating coating formed on the surface of these base materials is subjected to the following deposition conditions by an ion plating method (hot cathode method). A platinum-colored watch case and watch band were obtained.
<Film formation conditions>
Evaporation source: Platinum electron gun: 10 kV, 500 mA
Gas: Argon gas Film forming pressure: 0.2 Pa
Acceleration voltage (bias voltage): Ground to -50V
Anode voltage: 60V
Filament voltage: 7V

  The surface hardness (Hv: micro Vickers hardness meter, 5 g load, holding time 10 seconds) of the platinum coating formed on the surfaces of the watch case and watch band obtained as described above was 1200. These watch cases and watch bands were excellent in scratch resistance, and were formed with a platinum film and a high-grade white coating.

  Moreover, the color evaluation by L *, a *, b * display system (CIE surface system) of the decorative coating layer (white coating) is 88 <L * <92, 1.8 <a * <2.5. 0 <b * <5.5.

  Further, the wristwatch case and wristband obtained as described above and the wristwatch case and wristband obtained in Example 5 were each subjected to a scratch test, and the adhesion of the coating to the base material was compared. The measuring instrument used for the scratch test is a HEIDON-14 type surface property measuring instrument.

  Hereinafter, a decorative part sample of Example 5 having a titanium carbide plated coating and a titanium carbide plated coating having a white color tone with a carbon atom content of 40 ± 10 atom%, and a carbon atom content of 5-15 atom%. A decorative part sample of Example 10 having a base layer composed of a titanium plating film and a titanium carbide plating film having a white color tone with a carbon atom content of 40 ± 10 atomic% was prepared, and the adhesion of the film (the critical load described later) was measured. It was measured.

  The measurement conditions were such that a diamond indenter with a tip angle of 90 ° and a tip curvature radius of 50 μm was used, the scratching speed was 30 mm / min, and the scratching load was changed from 50 gf to 300 gf every 50 gf.

  This measurement result shows that the resistance value changes abruptly when the scratch load exceeds a certain value due to the scratch load and the resistance value after scratching. This is because the scratch resistance value increases linearly as the load increases, but when the critical load is exceeded, cracks occur in the coating formed on the substrate and chipping peeling occurs. . Then, due to the generated cracks and chipping peeling, the scratch resistance value increases rapidly, and the friction coefficient increases. The adhesion force of the film to the substrate can be evaluated by the value of the critical load. Here, the point of the scratch load which changed rapidly was observed with an optical microscope, and the adhesion strength of the coating was evaluated.

  In Example 5, chipping peeling occurred when the scratch load was 200 gf. On the other hand, in Example 10, chipping peeling occurred when the scratch load was 250 gf. That is, the critical load in Example 5 was 200 gf, and the critical load in Example 10 was 250 gf. From this, it is understood that the decorative part of Example 10 has a coating adhesion of 25% higher than that of the decorative part of Example 5.

In Examples 1 to 10, it goes without saying that a plating film made of tungsten carbide as a decorative substrate and chromium, hafnium, vanadium, or niobium as an underlayer can be formed. In Examples 1 to 10, watch cases and watch bands are manufactured, but it goes without saying that the techniques described in Examples 1 to 10 can also be applied to decorative items such as necklaces, pendants, brooches and the like.

Claims (47)

In a decorative article in which a decorative coating having a white color tone made of a noble metal or a noble metal alloy is formed by a dry plating method as an outermost layer,
A decorative substrate made of metal or ceramics;
An underlayer formed on the surface of the substrate;
A titanium carbide layer formed by dry plating on the surface of the underlayer;
The surface of the titanium carbide layer is composed of a decorative coating layer made of platinum or a platinum alloy formed by a dry plating method,
A decorative article having a white coating, wherein the titanium carbide layer has a thickness of 0.5 to 1.0 µm, and the decorative coating layer is a white coating having a thickness of 0.03 to 0.06 µm.   The decorative article having a white coating according to claim 1, wherein the underlayer is made of an alloy not containing nickel formed by a dry plating method or a wet plating method.   2. The white coating according to claim 1, wherein the decorative article base material is made of at least one metal selected from stainless steel, titanium, a titanium alloy, copper, a copper alloy, and tungsten carbide. Ornaments.   The ornamental base material is made of at least one metal selected from stainless steel, titanium, titanium alloy, copper, copper alloy, and tungsten carbide, and the base material surface is mirror surface, satin, hairline pattern, honing The decorative article having a white coating according to claim 1, wherein at least one surface finish selected from a pattern, a stamping pattern, and an etching pattern is applied. The decoration base material is made of zirconia ceramics, and its composition includes 3 to 7% by weight containing a stabilizer of yttrium oxide (Y ₂ O ₂ ), magnesium oxide (MgO) or calcium oxide (CaO). The decorative article having a white film according to claim 1, which is made of zirconia and has a white color tone.   Titanium (Ti), chromium, in which the base material for decoration is made of a metal other than copper and a copper alloy, or ceramics, and the base layer formed on the surface of the base material is formed by a dry plating method 6. The white color according to claim 1, wherein the white film is made of (Cr), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), or tantalum (Ta). A decorative article with a coating. The decorative article base material is made of a metal other than copper and a copper alloy, or the ceramics, and the base layer formed on the base material surface is formed by a dry plating method, and has a carbon atom content of 5 ˜15 atomic% titanium carbide (TiC), chromium carbide (Cr ₃ C ₂ ), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tungsten carbide (WC) or The decorative article having a white coating film according to any one of claims 1 to 5, which is an inclined film formed of a metal compound film made of tantalum carbide (TaC).   The decorative base material is made of a metal other than copper and a copper alloy, or the ceramic, and the base layer is formed by a dry plating method. The thickness is 0.02 to 0.2 μm, preferably 0.05. The decorative article having a white coating film according to claim 1, wherein the decorative article has a white coating film.   The decorative article base material is made of copper or a copper alloy, and the base layer is formed on the surface of the base material by a wet plating method. The nickel coating has a thickness of 1 to 10 μm, and the nickel coating surface is wet-plated. The decorative article having a white coating according to any one of claims 1, 3, and 4, comprising an amorphous nickel-phosphorus alloy coating having a thickness of 3 to 10 μm formed by a method.   Copper, palladium, copper-tin alloy, copper-tin-zinc alloy, and copper-tin-, wherein the base material for decorative articles is made of copper or a copper alloy, and the underlayer is formed by a wet plating method. The decorative article having a white coating film according to any one of claims 1 to 4, wherein the decorative article is a coating film having a thickness of 2 to 9 µm and comprising at least one selected from palladium alloys.   A mixture of titanium carbide forming the titanium carbide layer and platinum or a platinum alloy forming the decorative coating layer having a thickness of 0.005 to 0.04 μm between the titanium carbide layer and the decorative coating layer. It has a layer, The ornament which has a white film in any one of Claims 1-10 characterized by the above-mentioned.   The stainless steel coating layer having a thickness of 0.05 to 1.5 μm formed by a dry plating method is provided between the titanium carbide layer and the decorative coating layer. A decorative article having the white coating described.   The stainless steel coating layer comprises carbon 0.01 to 0.12% by volume, silicon 0.1 to 1.5% by volume, manganese 1.0 to 2.5% by volume, nickel 8 to 22% by volume, chromium 15 to The decorative article having a white coating according to claim 12, wherein the decorative article is made of austenitic stainless steel having a composition of 26% by volume and the balance being iron. The color evaluation by the L *, a *, b * color system (CIE system) of the decorative coating layer is as follows:
85 <L * <95, 1.5 <a * <4.0, 4.5 <b * <6.5,
The decorative article having a white coating according to claim 1 or 11, wherein the decorative article has a white coating. Δ values of L *, a *, and b * of the decorative coating layer formed on the decorative article base material that has been subjected to various surface finishes,
ΔL * = ± 6.0, Δa * = ± 1.55, Δb * = ± 2.25
The decorative article having a white coating according to claim 1 or 11, wherein the decorative article has a white coating.   The means for forming each of the underlayer, the titanium carbide layer, the mixed layer, and the decorative coating layer is at least one of a sputtering method, an ion plating method, and an arc method. A decorative article having a white coating according to any one of 1, 2, 6 to 8, 11, and 12.   The part of the surface of the decorative coating layer has at least one coating film formed by a dry plating method or a wet plating method and having a color tone different from that of the decorative coating layer. A decorative article having a white coating according to any one of the above.   The decorative article having a white coating film according to claim 17, wherein the coating film having a color tone different from that of the decorative coating layer is made of an alloy containing no nickel.   19. The white coating film according to claim 17, wherein the coating film having a color tone different from that of the decorative coating layer is made of gold, gold alloy, titanium nitride, zirconium nitride, hafnium nitride, or diamond-like carbon (DLC). Ornaments.   The coating film having a color tone different from that of the decorative coating layer has a two-layer structure of a lower layer made of titanium nitride, zirconium nitride or hafnium nitride and an upper layer made of gold or a gold alloy. A decorative article having the white coating described in 1.   A titanium coating and a silicon coating formed on the surface of the titanium coating between the decorative coating layer and a diamond-like carbon (DLC) coating which is a coating having a color different from that of the decorative coating layer; 20. A decorative article having a white coating according to claim 17 or 19.   The decorative article having a white coating according to claim 1, wherein the decorative coating layer is a mixed layer composed of titanium carbide forming a titanium carbide layer and platinum or a platinum alloy.   The decorative article having a white coat according to any one of claims 1 to 22, wherein the decorative coat layer has a surface hardness (Hv: micro Vickers hardness meter, 5 g load) of 1000 to 2000.   The decorative article having a white coating according to any one of claims 1 to 23, wherein the decorative article is a watch exterior part. In a method for manufacturing a decorative article in which a decorative coating having a white color tone made of a noble metal or a noble metal alloy is formed by a dry plating method as an outermost layer, a material made of metal or ceramics is used, and a base material for decorative goods is used by various processing means. Manufacturing process;
Forming a base layer on the substrate surface by a dry plating method or a wet plating method;
Forming a titanium carbide layer on the surface of the underlayer by a dry plating method;
Forming a decorative coating layer made of platinum or a platinum alloy as an outermost layer by a dry plating method on the surface of the titanium carbide layer, and producing a decorative article having a white coating.   The method for manufacturing a decorative article having a white coating according to claim 25, wherein the underlayer is made of an alloy containing no nickel and is formed by a dry plating method or a wet plating method.   26. The white color according to claim 25, wherein the decorative article base material is made of at least one metal selected from stainless steel, titanium, titanium alloy, copper, copper alloy, and tungsten carbide. A method for producing a decorative article having a coating.   The ornamental base material is made of at least one metal selected from stainless steel, titanium, titanium alloy, copper, copper alloy, and tungsten carbide, and the base material surface is mirror surface, satin, hairline pattern, honing 26. The method for producing a decorative article having a white coating according to claim 25, wherein at least one surface finish selected from a pattern, a stamping pattern, and an etching pattern is applied. With respect to 100 parts by weight of the stabilized zirconia powder in which the decorative article base material contains 3 to 7% by weight of a stabilizer of yttrium oxide (Y ₂ O ₂ ), magnesium oxide (MgO) or calcium oxide (CaO), A material containing 20 to 25 parts by weight of a binder is formed by injection molding, and then formed through a roughing process, degreasing, baking, grinding and polishing steps by machining, and exhibits a white color tone. Item 26. A method for producing a decorative article having the white coating according to Item 25. As the base layer, titanium (Ti), chromium (Cr), zirconium (Zr), hafnium (hafnium) is formed on the surface of the base material for decorative articles made of metal other than copper and copper alloy, or ceramics.
30. The decorative article having a white coating according to claim 25, wherein a coating made of Hf), vanadium (V), niobium (Nb), or tantalum (Ta) is formed by a dry plating method. Production method. On the surface of a decorative substrate made of a metal other than copper and copper alloy or the ceramics, titanium carbide (TiC) or chromium carbide (Cr ₃ C ₂ ) having a carbon atom content of 5 to 15 atomic% is used as the base layer. ), Zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tungsten carbide (WC), or tantalum carbide (TaC), a gradient film which is a metal compound film is dry-plated. The method for producing a decorative article having a white film according to any one of claims 25 to 29, wherein   As a base layer, a film having a thickness of 0.02 to 0.2 μm, preferably 0.05 to 0.1 μm, is applied to the surface of the decorative substrate made of a metal other than copper and copper alloy, or ceramics by a dry plating method. 32. The method for producing a decorative article having a white coating according to claim 25, wherein the decorative article is formed.   A nickel coating with a thickness of 1 to 10 μm is formed as a base layer on the surface of a decorative material substrate made of copper and a copper alloy by a wet plating method, and an amorphous nickel-phosphorus alloy with a thickness of 3 to 10 μm is formed on the surface of the nickel coating. 29. The method for producing a decorative article having a white coating according to claim 25, wherein the coating is formed by a wet plating method.   From the at least one selected from the group consisting of copper, palladium, copper-tin alloy, copper-tin-zinc alloy and copper-tin-palladium alloy as the base layer on the surface of the decorative substrate made of copper or copper alloy The method for producing a decorative article having a white coating according to any one of claims 25 to 28, wherein the coating having a thickness of 2 to 9 µm is formed by a wet plating method.   A mixture of titanium carbide forming the titanium carbide layer and platinum or a platinum alloy forming the decorative coating layer having a thickness of 0.005 to 0.04 μm between the titanium carbide layer and the decorative coating layer. The method for producing a decorative article having a white coating according to any one of claims 25 to 34, wherein the layer is formed by a dry plating method.   35. A stainless steel coating layer having a thickness of 0.05 to 1.5 [mu] m is formed between the titanium carbide layer and the decorative coating layer by a dry plating method, according to any one of claims 25 to 34. A method for producing a decorative article having a white coating.   As the stainless steel coating layer, carbon 0.01 to 0.12% by volume, silicon 0.1 to 1.5% by volume, manganese 1.0 to 2.5% by volume, nickel 8 to 22% by volume, chromium 15 to The coating film made of austenitic stainless steel having a composition of 26% by volume and the balance being iron is formed by at least one of a sputtering method, an ion plating method, and an arc method. A method for producing a decorative article having a white coating.   The underlayer, the titanium carbide layer, the mixed layer, and the decorative coating layer are formed by at least one of a sputtering method, an ion plating method, and an arc method. The manufacturing method of the ornament which has a white film in any one of 26,30-32,35,36.   The production of the decorative article having a white coating according to any one of claims 25, 35, and 36, wherein the titanium carbide layer and / or the mixed layer is formed by dry plating using methane gas. Method.   The white color according to any one of claims 25 to 36, wherein at least one coating film having a color tone different from that of the decorative coating layer is formed on a part of the surface of the decorative coating layer by a dry plating method or a wet plating method. A method for producing a decorative article having a coating.   41. The method for producing a decorative article having a white coating according to claim 40, wherein the coating having a color tone different from that of the decorative coating is made of an alloy not containing nickel and is formed by a dry plating method or a wet plating method.   The white coating according to claim 40 or 41, wherein gold, gold alloy, titanium nitride, zirconium nitride, hafnium nitride or diamond-like carbon (DLC) is formed as a coating different from the color tone of the decorative coating layer. A method for manufacturing a decorative article.   The film having a two-layer structure of a lower layer made of titanium nitride, zirconium nitride or hafnium nitride and an upper layer made of gold or a gold alloy is formed as a film having a color tone different from that of the decorative coating layer. 41. A method for producing a decorative article having a white coating according to 41.   A titanium coating is formed between the decorative coating layer and a diamond-like carbon (DLC) coating which is a coating having a color tone different from that of the decorative coating layer, and a silicon coating is further formed on the surface of the titanium coating. The manufacturing method of the ornament which has a white film of Claim 40 or 42 to do.   36. The decorative article having a white coating according to any one of claims 25 to 35, wherein the decorative coating layer is a mixed layer comprising titanium carbide forming a titanium carbide layer and platinum or a platinum alloy. Production method.   The method for producing a decorative article having a white coating according to any one of claims 25 to 45, wherein the decorative coating layer has a surface hardness (Hv: micro Vickers hardness meter, 5 g load) of 1000 to 2000.   47. The method for manufacturing a decorative article having a white coating according to claim 25, wherein the decorative article is a watch exterior part.